They don't claim to be made by SmartThings Inc. They just sell it.
The second one has an older FCC ID T3L-SS014
(2015) than the other one 2AF4S-STS-IRM-250
(2016). Neither has been manufactured by Samsung or the SmartThings subsidiary. They come from CentraLite Systems, Inc and SAM JIN CO., LTD respectively. The former also used a factory or a partner in Mexico to produce it. Of course, that doesn't say anything about when they were actually produced.
Also the upper one is missing the European CE logo, so it could just be a US only version. Furthermore, SmartThings was only acquired by Samsung in late 2014 so maybe the only started to go out with Samsung SmartThings with the later model.
So the original SmartThings Inc before being bought probably had a partner in Mexico and Samsung shifted the production to a Korean partner/subsidiary — I'm not gonna investigate Korean Samsung corporate structures — after they bought it.
Long story short, doesn't look fishy to me.